1 Between forty-five and thirty-six million years ago a primitive, carnivorous mammal roamed the Earth. It was a hoofed mammal (ungulate) that lived during the late Eocene epoch. This animal was believed to be the largest predatory ungulate that ever lived. Scientists believe this mammal was more closely related to hippos and pigs rather than traditional predatory mammals.2 A fossilized giant three-foot skull and a few bones of this animal were found in Mongolia in 1923. The fossils led scientists to believe it was a wolf-like animal that was heavily built. They believed it to be anywhere between eleven to eighteen feet long and about five feet tall. They believe it weighed nearly a ton. It had four short legs, a long body, a long tail, and a long snout. It had large sharp teeth in front and flat cheek teeth that were used to crush bones.